Systematic shifts in the variation among host individuals must be considered in climate-disease theory
Data files
Nov 27, 2024 version files 1.45 MB
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CODE_ARCHIVE_FINAL.zip
1.45 MB
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README.md
6.40 KB
Abstract
To make more informed predictions of host-pathogen interactions under climate change, studies have incorporated the thermal performance of host, vector, and pathogen traits into disease models to quantify effects on average transmission rates. However, this body of work has omitted the fact that variation in susceptibility among individual hosts affects disease spread and long-term patterns of host population dynamics. Furthermore, and especially for ectothermic host species, variation in susceptibility is likely to be plastic, influenced by variables such as environmental temperature.For example, as host individuals respond idiosyncratically to temperature, this could affect the population-level variation in susceptibility, such that there may be predictable functional relationships between variation in susceptibility and temperature.Quantifying the relationship between temperature and among-host trait variation will therefore be critical for predicting how climate change and disease will interact to influence host-pathogen population dynamics. Here, we use a model to demonstrate how short-term effects of temperature on the distribution of host susceptibility can drive epidemic characteristics, fluctuations in host population sizes, and probabilities of host extinction. Our results emphasize that more research is needed in disease ecology and climate biology to understand the mechanisms that shape individual trait variation, not just trait averages.
https://doi.org/10.5061/dryad.f1vhhmh60
Description of the data and file structure
The archived files include two .ZIP
CODE_ARCHIVE_FINAL.zip: R scripts and data for generating Figures 1, 2, 3, 5, and 6 of the main text, along with archived original Figure images. The archive is organized into sub-directories. There is a separate sub-directory for each figure. Each sub-directory has a .R script for generating the applicable figures.
./fig1cv_temp.Rsimulates synthetic data to construct Figure 1 of the manuscript
./fig2cv_temp_data.Rdigests the data (as described in the next bullet points) to generate Figure 2./AltmancontainsAltman_tadpoles_data.csvwhich are raw data from Altman et al. 2016 JAE, which are used to generate the lower panel of Figure 2. Note that these data were not collected by us as authors but are publicly available data that we used to create panels in our figure. The required fields from this data file areAdjPropEncystedandPerfTemp. However, all variables are described below. Also note that blank values (i.e., NA values) are sometimes present if the animal of question did not live to the time of that data measurement.TadIDIndividual tadpole identificationBlockTemporal blockClutch Tadpoleclutch of origin identificationAccGraph1Category of tadpole acclimation temperature used for Fig. 3B of Altman et al.AccGraph2Category of tadpole acclimation temperature used for Fig. 4 (both A & B) of Altman et al.AccTempTadpole acclimation temperature in degrees CelciusAccIncIdentification of the incubator in which the tadpole was kept during the 3-week acclimation periodPerfTempPerformance temperature in degrees CelciusPerfIncIdentification of the incubator in which the tadpole was kept during the performance period (following the temperature switch)InitialGosnerTadpole Gosner stage at the beginning of the acclimation periodExposureGosnerTadpole Gosner stage at time of exposure to R. ondatraeFinalGosnerTadpole Gosner stage at the end of of the experiment (2 weeks post-exposure to R. ondatrae)InitialMassTadpole mass (mg) at the beginning of the acclimation periodExposureMassTadpole mass (mg) at time of exposure to R. ondatraeFinalMassTadpole mass (mg) at the end of the experiment (2 weeks post-exposure to R. ondatrae)Cysts1Number of metacercariae present in tadpole 12 hours post-exposure to R. ondatraeCysts7Number of metacercariae present in tadpole 7 days post-exposure to R. ondatraeCysts14Number of metacercariae present in tadpole 14 days post-exposure to R. ondatraePropCleared1Proportion of metacercariae cleared by the tadpole between 12 hours and 7 days post-exposure to R. ondatrae (Fig. 4A of Altman et al.)PropCleared2Proportion of metacercariae cleared by the tadpole between 7 and 14 days post-exposure to R. ondatrae (Fig. 4B of Altman et al.)PropEncystedRaw proportion of parasites to encyst in each tadpole (“Cysts1”/20)LeftoverCercNumber of cercariae that failed to encyst in the tadpole (found in the exposure water after the 12 hour exposure period)AdjPropEncystedSame as “PropEncysted”, except max value is 1 (1.05 values were changed to 1) to allow for arcsine square root transformation (Fig. 3B)
./Six-Viruses-Tempcontains raw data from Shocket et al. 2020 Elife, which are used to generate the top and middle panel of Figure 2. Shocket et al. 2020 gathered data from several studies. Note that these data were not collected by us as authors but are publicly available data that we used to create panels in our figure. We used two data filesTraitData_bc.csvandTraitData_lf.csv. Note that we only considered Cx. pipiens (Cpip) and West Nile virus (WNV). The file attributes are defined as follows:seriesIDseries ID with the name of the person who digitized the data from the published papertrait.nametrait abbreviation, which is often the model parameter- 1/mu, lifespan (days; the inverse of mortality rate, mu (lf 1/mu))
- bc, vector competence (propotion; bc full vector competence # transmitting / # exposed; c infection efficiency # infected / # exposed; b transmission efficiency # transmitting / # infected)
Ttemperature (C)traittrait valueErrorPosSI&ErrorNegSIstandard errors for the trait value, if "NA" then not enough data was available to calculate the value.Trait2.namesecond variable in the experiment, if needed; for vector competence this is usually timehost.codefour letter code for mosquito vector species- Cpip Cx. pipiens, Cqui Cx. quinquefasciatus, Ctar Cx. tarsalis, Cuni Cx. univittatus, Cthe Cx. theileri, Atri Ae. triseriatus, Atae Ae. taeniorhynchus, Avex Ae. vexans, Cmel Cs. melanura, Cmol Cx. pipiens molestus, Cpal Cx. pipiens pallens, Cres Cx. restuans, Ador Ae. dorsalis, Anig Ae. nigromaculis, Asol Ae. sollicitans, Asal Ae. salinarius
paras.codefour letter code for parasite (virus)Citationfirst author, year of publication, and journal name for publication the data came fromFigurethe figure or table that the data came from in the original publicationNotesany notesjoint.codeeight letter code for combination of mosqutio vector species and virus (host.code + paras.code, for infection traits only)
./fig3fig3-R02.Rsimulates synthetic data to construct Figure 3 of the manuscript
./figs5_6emp_var_SEIP.Rsimulates synthetic data to construct both Figures 5 and 6 of the manuscript
Code/software
ESM_FINAL.zip: R and QMD scripts for generating the Electronic Supplementary Materials files
- There are three file types: .R, .QMD, and .PDF
- The user can run the .QMD file, which sources the two .R scripts but should run as long as the user has specified the correct working directory.
- The .QMD can be rendered into .HTML or .PDF
- The two .R scripts contain helper functions
- The .PDF contains the archived version of the rendered .QMD
R scripts and data used to generate figures and supplementary materials for manuscript.
